It is known to provide a sheet feeder having a tray for receiving one stack of sheets and then to feed the sheets seriatim from the bottom of the stack. Feeders of this type have been used, for example, for feeding document sheets in an electrographic copier seriatim from a tray to a station where the sheets are illuminated for copying. The sheets in the stack represent a job to be copied. When the operator wishes to copy another stack of sheets comprising a second job, the operator waits until all sheets of the first stack have been fed from the tray before the tray is loaded with the second stack of sheets. Although this procedure works satisfactorily, it does require the operator to be at the copier when the first job has been fed from the tray in order to load the second job into the tray. Clearly it would be advantageous to allow two jobs to be fed sequentially by the sheet feeder and without the need for further operator intervention after the first job is completed. Such would reduce the time the operator is required to be at the copier and also increase the productivity of the copier by reducing the time when the copier is not operating.